1. Technical Field
The present invention relates to a device and a method that enables a subsequent evaluation of a process in a motor vehicle where a safety device in the vehicle, for example an airbag, has not triggered. The invention is particularly intended for use in connection with airbags provided in trucks, but may also be applied in other types of motor vehicles and to other types of safety devices.
2. Background of the Invention
Many types of motor vehicles, for example trucks, are provided with various types of safety devices, such as, for example, airbags, which are triggered by means of control equipment in the event of certain types of specified processes or occurrences, or when one or several parameters exceed a certain threshold value which has been set beforehand.
In order to enable a subsequent evaluation of what has happened in a vehicle when a safety device has triggered, the control equipment for the safety devices are often provided with the capacity of storing a number of different parameters during such a process, such as, for example during a collision. One drawback related to such equipment is that they do not provide the opportunity to analyze what has happened in connection with a process where the safety device has not triggered, even if the vehicle has been in a situation where the safety device has come close to being triggered, or perhaps where it should have been triggered.
If a safety device in a vehicle has not triggered when the vehicle has been involved in a collision or some other situation where the driver believes that the safety device should have triggered, today""s known devices offer no possibility for the manufacturer to evaluate what has occurred, and thus to understand the reason for why the safety device has not triggered. Such an evaluation would result in considerably improved possibilities to develop the safety devices further, and to assist the vehicle""s driver in understanding why the safety device has not triggered.
One possibility to obtain information of what has happened at a certain time, irrespective of whether a safety device has triggered or not, is provided by means of so-called data logging systems. Known systems of this type, however, require considerable space, which, on account of the limited amount of space that is available for placing additional equipment in today""s vehicles, makes it difficult to install such systems. Moreover, data logging systems are comparatively expensive, and in most cases do not offer the kind of resolution of collected data that is desirable in order to make it possible to analyze a process of the type in question with the desired accuracy. Moreover, the data that is collected by means of data logging systems is mostly of a nature that is focused on the behavior of the driver, not data, that makes it possible to evaluate why a safety device has not triggered.
Thus, there is a demand for equipment that enables a subsequent analysis of what has happened when a safety device in a vehicle has not triggered. One further desired feature regarding such equipment is that it can be easily integrated into existing equipment so that it does not take up too much space in the vehicle.
The present invention meets this desire by means of the fact that it provides a device for use in a motor vehicle that enables subsequent analysis of processes where a safety device in the vehicle has not triggered. The invention comprises (includes, but is not limited to) a control device for a safety device, and a sensor for the detection of processes and occurrences that can result in a safety device being triggered if a first parameter exceeds an upper limit. The invention also comprises a first memory in which parameters regarding the operation of the vehicle are stored when the first parameter exceeds a lower limit. A second memory is provided and to which the parameters are transmitted if the safety device is triggered. Furthermore, the invention comprises means for transmitting the parameters from the first memory to the second memory if the first parameter exceeds the lower limit during a certain time period and the amount of data in the first memory exceeds a predetermined limit.
Due to the fact that the invention provides the possibility to utilize the existing control device for the safety device in question, there is no demand for any additional space for installing the device in the vehicle. Moreover, this results in a device that, according to the invention, can be integrated into the vehicle in an economical manner and also be installed in existing vehicles by means of an exchange of the control unit. Furthermore, seeing that the invention utilizes essentially existing components, the cost for a device provided according to the invention can be kept low.
The invention also comprises methods of utilization of devices configured according to the structural teachings above.